Temperature and pressure measurements in a slim package for downhole operations. These sensors are based on comertial pressure transducers made by TE-Connectivity (the MS5803 series), which are then molded in high strength epoxy to allow them to be submerged for sensing. This unit can be placed in a protective brass housing which protects the delicate membrane of the pressure treansducer from damage, while still allowing accurate pressure measurment.
- Full I2C interface
- Available RS-485 option allows extremely long cable runs
- Customizable system design, several MS5803 transducers are available, with different pressure ranges, all of which are pin swapable, meaning the same PCB can be used
- Additonal thermistor on board for higher accuracy temp measurment compaired to the internal temp sensor on the MS5803
- Extremely small size
The pinout of the device is the same across all models, and consists of SDA (White), SCL (Green), Vcc (Red), and GND (Black). This pinout is shown below for clarity
Below are a table of specifications for the different TP-Downhole models
General Model Notes:
- Regardless of input voltage, all logic is 3.3v
- All "b" type models do not have additional temp sense ADC to prevent address collision, and the MS5803 uses the alternate 0x76 I2C address for the same reason
| Model Code | Vcc [V] | Reverse Polarity Protection | Pressure | MS5803 Address |
|---|---|---|---|---|
| 2v1 | 3.3v | No | 2BA | 0x77 |
| 5v1 | 3.3v | No | 5BA | 0x77 |
| 2v2 | 3.3v ~ 5.5v | Yes | 2BA | 0x77 |
| 2b2 | 3.3v ~ 5.5v | Yes | 2BA | 0x76 |
| 2A2 | 3.3v ~ 5.5v | Yes | 2BA | 0x76 |
| Model Code | Thermistor β Value | R_25 [kΩ] | R_0 [kΩ] | VRef [V] |
|---|---|---|---|---|
| 2v1 | 3435 | 10 | 47 | 3.3 |
| 5v1 | 3435 | 10 | 47 | 3.3 |
| 2v2 | 3435 | 10 | 10 | 1.8 |
| 2b2 | N/A | N/A | N/A | N/A |
| 2A2 | 3435 | 10 | 10 | 1.8 |
MS5803-05 (dive watch module, to 500 kPa, up to 4mm resolution):
MS5803-01 (barometer module that can be shallowly submerged, to 130 kPa, up to 1mm resolution):
Additional pressure sensors exist in this series for deeper depths, but with correlated lower resolutions.
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